System and method for integrated control of supply fan

ABSTRACT

The present disclosure describes a supply fan assembly including a controller, a memory operably coupled with the controller. The supply fan assembly further includes at least one environment sensor operably coupled with the controller and a fan supplying fresh air from an exterior environment into a structure according to instructions from the controller. Additionally, the operational data is generated by the at least one of the environment sensor and the controller, and the controller instructs the fan in response to the operational data generated during a pre-defined time period.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. provisional patentapplication No. 62/614,848, filed on Jan. 8, 2018; and U.S. provisionalpatent application No. 62/614,840, filed on Jan. 8, 2018, the entiredisclosure thereof being hereby incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates generally to a system and method forintegrated operation and control of an air ventilation unit. Moreparticularly, the subject matter disclosed herein relates to a systemwith integrated control components for operation of supply fan units andmethods of controlling supply fan units during operation withinbuildings.

BACKGROUND

In warm and/or humid climates, such as those found in much of the UnitedStates and Central America, challenges exist for air distributionsystems. Conventional outside air distribution systems for homeventilation include ducting connected between a port to outside air(i.e., inlet port) and a supply fan unit and further connected to an airhandler unit (AHU). A motorized damper is positioned within the ductingand may be energized and driven by a controller for a period of time tocontrol a quantity of outside air supplied to the AHU. The quantity ofoutside air supplied into the AHU may be regulated to comply withapplicable standards/codes, such as the American Society of Heating,Refrigeration, and Air Conditioning Engineers (ASHRAE) ventilationrequirements and/or applicable building code ventilation requirements.Often times, a conventional system is referred to as an “Air Cycler”,“Air Exchanger”, or “Central Fan Integrated System” (CFIS). Some modelsof CFIS are connected to a humidity sensor, located either outside orinside of a home or other building, and/or a temperature sensor locatedoutside of the home. The use of humidity sensor(s) and temperaturesensor(s) typically require wiring between the controller and thesensors.

If a humidity sensor is located in the home, the controller of thetypical CFIS, or a supply fan unit thereof, prevents ventilation whenthe inside humidity level (i.e., within the home) is undesirably high.Further, such a CFIS may prevent or stop ventilation when the outsidehumidity level is lower than the inside humidity level, thereby limitingthe ventilation of the serviced home. Limiting ventilation may increasethe risk of and/or quantity of pollutants being retained within the homebeing serviced. Alternatively, when a humidity sensor is located outsideof the home, wired and/or wireless communications connect the humiditysensor with the controller. Wireless communications may requirebatteries to energize the humidity sensor. This may represent increasedinstallation and maintenance costs as well as decreased robustness ofcommunication.

Examples of CFIS, or the supply fan that draws air into the CFIS, use ahumidity limit that is configured manually every season in order toavoid condensation in ducting of the associated AHU. Most of the time,these manual configurations are preset limits that account forworst-case scenarios. Determining humidity limits based on worst-caseconditions may lead to significantly reduced ventilation time duringhot/humid seasons. As previously noted, reduced ventilation time mayresult in increased pollutant retention within the servicedhome/building. Finally, the locations of the temperature sensor(s) forCFISs, air supply fans, or air exchangers must be carefully chosen toprevent outside conditions from influencing and/or altering the readingsof the temperature sensor(s). Temperature sensor(s) limit and/or reduceventilation if the accuracy of one or more temperature sensor(s) iscompromised by placement and/or outside temperatures that are unusuallycold or hot. In view of these challenges a CFIS, a supply fan unit, aircycler system, and/or outside air distribution system with improvedcontrol systems and methods of operation represent an improvement overconventional systems and components.

The description provided in the background section should not be assumedto be prior art merely because it is mentioned in or associated with thebackground section. The background section may include information thatdescribes one or more aspects of the subject technology.

SUMMARY

According to an aspect of this disclosure, the invention provides asystem with integrated control components for operation of supply fanunits and methods of controlling a supply fan unit during its operationwithin a building structure, such as a home. A supply fan unit includesa motorized damper that operates when the supply fan unit isoperational. The motorized damper is fluidly connected and/or directlyinstalled within the return side of the AHU. As such, the damper fluidlyconnects external, fresh air to the AHU thereby bringing fresh air fromthe exterior environment into the serviced structure, such as a home orbuilding structure.

Further, the present disclosure describes a supply fan assemblyincluding a controller, a memory operably coupled with the controllerand having operational data stored on the memory. The supply fanassembly further includes at least one environment sensor operablycoupled with the controller and a fan supplying fresh air from anexterior environment into a structure according to instructions from thecontroller. Additionally, the operational data is generated by the atleast one of the environment sensor and the controller, and thecontroller instructs the fan in response to the operational datagenerated during a pre-defined time period.

According to the present disclosure, a ventilation system includes acontroller, a memory or memory module operably coupled with thecontroller and configured to store a configuration table and aprediction table, and at least one sensor operably coupled with thecontroller. Also, the ventilation system includes a ventilation fan thatsupplies ambient air from an exterior environment to the ventilationsystem according to operating state instructions generated by thecontroller in response to the configuration table and the predictiontable wherein the operating state instructions of the ventilation fanare based upon both a timing of ventilation parameter and a rate ofventilation parameter.

Further, in this disclosure, a method of controlling inflow of fresh airduring an operation period of a ventilation fan includes the followsteps: collecting air values indicative of fresh air characteristics;storing the air values collected over a predetermined time period;controlling the inflow of fresh air during a ventilation cycle inresponse to the stored sensor signals; and operating a ventilation fanto draw fresh air into ducting for a ventilation period. According tothis method, the ventilation period is a part of the ventilation cycle,and the predetermined time period is greater than the ventilation cycle.

In an exemplary embodiment, the supply fan unit uses external sensorslocated outside the home and in communication with the supply fan unit.Such external sensors measure the conditions and characteristics of theoutside air, including air temperature, air humidity, particle sizepresent in the air, level of CO2, level of CO, and/or other qualities.Further, in example embodiments, the supply fan unit has integratedsensors to measure conditions and characteristics of the interior air.The supply fan unit comprises an air pressure sensor fluidly connectedto the AHU by ducting connected to the return ducting of the AHU,thereby detecting whether the AHU is operational. The supply fan unitmay further comprise an interlock feature with exhaust fans foractivating the supply fans so as to reach balanced ventilation.

A controller receives and processes one or more signals from one or moresensors. The controller uses the one or more sensor signals as inputs tooperate the supply fan unit according to building code ventilationrequirements and/or other predetermined operational parameters.Accordingly, the controller adjusts operations to manipulate inflow offresh air as part of the ventilation rate.

The air supply fan unit may be installed and operate in conjunction withan AHU, or in an autonomous mode. In the latter configuration, the airsupply fan unit may not be connected to an AHU, but rather operate toprovide air to the interior of the building independently from theoperation of an AHU. In this embodiment, the air supply fan unitoperates in a similar to an air supply fan unit connected to an AHU, asdescribed hereinbelow, but without interacting with sensor signals fromthe AHU and/or other AHU components (e.g., a wall control unit,thermostat, or another user input unit). The supply fan unit inaccordance with this embodiment therefore controls inflow of fresh airin the building in an optimized manner without receiving inputs from anAHU.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding and are incorporated in and constitute a part of thisspecification, illustrate disclosed embodiments and together with thedescription serve to explain the principles of the disclosedembodiments. In the drawings:

FIG. 1 is a perspective view of a supply fan unit in accordance with anembodiment of the invention;

FIG. 2A is an exploded view of the supply fan unit of FIG. 1;

FIG. 2B is an isometric view of a heating, ventilation, and airconditioning system with the supply fan unit installed between anarrangement of ducts;

FIG. 2C is an isometric view of the supply fan unit coupled with an airhandling unit and installed within a system of ducts;

FIG. 3A is a front view of a control interface associated with thesupply fan unit of FIG. 1;

FIG. 3B is a block diagram indicating a set of general operatingparameters of the supply fan unit of FIG. 1;

FIG. 3C is a prediction table for operation of the supply fan unit ofFIG. 1, according to an exemplary embodiment;

FIGS. 4A and 4B are configuration tables used for setting operatingconfigurations of the supply fan unit of FIG. 1;

FIG. 4C is an alternate configuration table for setting operatingconfigurations of the supply fan unit and graphically indicating therelationship between the configuration table and a temperature reading;

FIG. 4D is an alternate configuration table for setting operatingconfigurations of the supply fan unit and including cycle times anddecision triggers;

FIG. 4E is a map of the U.S.A. illustrating by region, in associationwith a legend, preferred modes of the configuration tables of FIGS.4A-4D;

FIG. 5 is a block diagram illustrating components and processes involvedin the operation of the supply fan unit;

FIG. 6 is a top-level flow chart illustrating operation logics of thesupply fan unit;

FIG. 7 is a wiring diagram illustrating electrical connections betweenthe supply fan unit of FIGS. 1 and 2, and the AHU with associatedcontrol;

FIG. 8 is a combined chart illustrating fresh air sampling data, AHUheating operation data, AHU heating operation data and predictioncurves;

FIG. 9 is a flow chart illustrating steps performed during a fresh airsampling process of the operating method;

FIG. 10 is a flowchart illustrating an operating process of the supplyfan unit;

FIG. 11 is a flowchart illustrating a ventilation decision process ofthe operating method of the supply fan unit;

FIG. 12 is a flowchart illustrating an updating process for a predictiontable, such as is shown in FIG. 3C, of the operating method;

FIG. 13 is a flowchart illustrating a process for starting ventilationwith the supply fan unit;

FIG. 14 is a flowchart illustrating a process for stopping ventilationwith the supply fan unit; and

FIG. 15 is a flowchart illustrating a ventilation target predictionprocess for the supply fan unit;

In one or more implementations, not all of the depicted components ineach figure may be required, and one or more implementations may includeadditional components not shown in a figure. Variations in thearrangement and type of the components may be made without departingfrom the scope of the subject disclosure. Additional components,different components, or fewer components may be utilized within thescope of the subject disclosure.

DETAILED DESCRIPTION

The detailed description set forth below is intended as a description ofvarious implementations and is not intended to represent the onlyimplementations in which the subject technology may be practiced. Asthose skilled in the art would realize, the described implementationsmay be modified in various different ways, all without departing fromthe scope of the present disclosure. Still further, modules andprocesses depicted may be combined, in whole or in part, and/or divided,into one or more different parts, as applicable to fit particularimplementations without departing from the scope of the presentdisclosure. Accordingly, the drawings and description are to be regardedas illustrative in nature and not restrictive.

Detailed below is a system with integrated control components foroperation of supply fan units and methods of controlling a supply fanunit during its operation within a building structure, such as a home.The supply fan unit may be a means of providing outside air to aserviced home. The air may be supplied at a flow rate associated withthe supply fan. The supply fan unit may be partly operable with,compatible with, and/or integrated into an air cycler system, an outsideair distribution system, an air exchanger, and/or any other systemdesigned to controllably allow and/or forcibly generate fresh airflowfrom the exterior environment of a building structure into the interiorenvironment of the building structure. Further, a control systemdescribed herein may be applied to the ventilation and HVAC systemslisted above alternatively and/or in addition to the supply fan unit.

An air handler unit (AHU) may be a device servicing the buildingstructure in at least one of heating, cooling/air conditioning, heatrecovery, energy recovery, and/or air circulating/ventilating thebuilding structure. The AHU may alternatively or additionally servicethe building structure with dehumidifying, humidifying, and/or airfiltering functions.

The terms “building,” “house,” “home,” and/or “structure” may refer toone or more edifices that may be serviced by an AHU with respect toheating, ventilating, and air conditioning, and by an associated supplyfan unit. The expressions “outside air” and “fresh air” may be usedinterchangeably and refer to air controllably allowed into the airhandler unit and/or forcibly taken from the exterior environment. Theoutside air or fresh air may vary in temperature and/or humiditydepending on the conditions of the exterior environment. “Inside air” or“interior air” is the air already present, at a given time, in theserviced home before addition of fresh air. Further, “outside,”“ambient,” “environment,” and “exterior” refer to the broader spacewithin which the building defines an enclosed space, inside, and/orinterior that is serviced by the AHU.

Referring now to FIGS. 1 and 2, a supply fan unit 20 comprises a housing22, an inlet port 24, and an outlet port 26. The supply fan unit 20 maybe installed in the building with the inlet port 24 connected to anoutside ducting in fluid connection with the exterior environment. Inaccordance with this configuration, the supply fan unit 20 is capable ofdrawing fresh air into the building interior. The outlet port 26 isconnected to an inside ducting that may be fluidly connected withanother component, such as an AHU 160 (see FIG. 2C). The outlet port 26controllably supplies the AHU 160 with fresh air. The housing 22 definesan enclosed environment or internal cavity within the supply fan unit 20thereby preventing outside air from uncontrollably flowing into theinternal cavity 23 within which the air supply unit 20 is installed. Theclosed environment within the housing also prevents unfresh air of thebuilding interior (e.g., the attic of the building) from mixing withfresh, incoming air from the exterior environment.

The air supply unit 20 defines an interior airflow passageway from theinlet port 24 through a filter 132 and into the internal cavity 23 tothe outlet port 26, as depicted in FIG. 2A. Further along the airflowpassageway, the fresh air encounters integrated sensors or environmentsensors such as a temperature sensor 34 and a humidity sensor 36.According to exemplary embodiments, one or more other suitableintegrated and/or external sensors may alternatively or additionally bepresent within the internal cavity 23 and along the interior airflowpath. Next, the fresh air passing along the airflow passageway ispropelled by a fan 42 towards the outlet port 26. A controllable damper52 is manipulated between open, closed, and intermediate positions. Thecontrollable damper 52 traverses the airflow passageway beyond theforegoing components, but before the outlet port 26. The position of thecontrollable damper 52 and the controllable speed of the fan 42 maymanipulate the airflow passageway and the flow rate of fresh air as theairflow is discharged through the outlet port 26 and from the air supplyfan unit 20. The airflow may be controllable within a range ofrelatively no airflow to a maximum airflow rate. Additional informationconcerning the damper 52 and damper control assemblies may be found inco-pending U.S. patent application Ser. No. 16/242,498, filed Jan. 8,2019 and titled “DAMPER CONTROL ASSEMBLY & METHOD FOR USE IN AIR FLOWSYSTEM”, the entire disclosure of which is hereby incorporated byreference herein.

The air supply unit 20 further comprises a controller 120 forcontrolling the damper 52 and the fan 42. The integrated sensors 34, 36are also connected to the controller 120, which resides with anenclosure cover 38. Additional electrical/electronic components, such asone or more printed circuit boards (PCBs) and/or other control circuitryare also housed within the cover 38. The cover 38 may protect thecontroller 120 and other electrical components from undesirable humancontact and/or prevent the accumulation of humidity and rapidtemperature variation from affecting the enclosed controller 120 andother enclosed electric/electronic components. Referring still to FIG.2A, the air supply unit 20 is powered and may be connected to the gridof the building via one or more power leads 48. The power transmitted bythe one or more power leads 48 powers the various components (e.g., thecontroller 120, the fan 42, the damper 52, the temperature sensor 34,humidity sensor 36, and/or other components therein). In an exemplaryembodiment, the air supply unit 20 may have a hardwired connection tothe electrical grid of the building thereby omitting use of an outlet.

The air supply unit 20 may be powered by a one or more of sources. Thefan 42 may powered by the one or more power leads 48 and/or otherwiseconnected to the power grid of the building. The controller 120 may bepowered with, for example, a 24V (volt) power source or the 110V powergrid. In an exemplary embodiment, the 24V power source may be providedby a component of the AHU 160 such as, for example, the transformer ofthe AHU 160. According to another embodiment, the air supply unit 20comprises a transformer connected to the power grid of the building. Thetransformer may transform the grid power to provide desired powercharacteristics. Further, the controller 120 may be powered by a directcurrent (DC) power source.

Referring now to FIG. 2B, the supply fan unit 20 of FIG. 2A-2C, with thedamper control assembly 20 incorporated therein, is shown disposedwithin an HVAC system 154. Upstream ducts 156 and downstream ducts 158are coupled to the inlet port 124 and the outlet port 126, respectively,of the supply fan unit 20.

In exemplary embodiments, an in-line heater 162, sized according toairflow and outside design heating temperature from Manual J (a protocoldeveloped by the Air Conditioning Contractors of America (ACCA)) orASHRAE specifications, may be installed to heat the air delivered to theAHU 160 to an acceptable operating temperature. For example, it may bedesirable to maintain a minimum temperature of 55° F. for all airpassing through the AHU 160. The in-line heater 162 may have anintegrated airflow sensor and a temperature sensor to prevent heating inno-flow or low-flow conditions, during which heating is typically notdesirable. The heater 162 is coupled with an air inlet 164 through whichfresh air flows to the heater 162. The air passes from the heater 162through the duct 156 to the supply fan unit 20.

In FIG. 2C, the supply fan unit 20 is coupled by the duct 158 to the airhandling unit 160. Accordingly, fresh air is drawn in by the fan 142,through the supply fan unit 20, and through the duct 158 to the AHU 160.From there, the AHU 160 may distribute the air through further ductingor operate in another suitable manner. The present disclosurecontemplates the installation of the herein described damper controlassembly within other ducting and/or other HVAC systems, including anAHU and/or one or more air outflow fan units.

Referring now to FIG. 3A, the air supply unit 20 comprises controlinterface 70 operable by a user to input a selected configuration fromamong a plurality of possible configurations. The control interface 70may include integrated switches 72, integrated push-buttons, integratedtoggles, and/or integrated button-type controls such as potentiometers74. In an exemplary embodiment, an external control module may be incommunication with the air supply unit 20 and comprise one or moresimilar controls. The air supply unit 20 comprises a display (not shown)comprising one or more light/LEDs. The behavior of the one or more LEDs(e.g., off, on, flashing, flashing sequence, and duration) may indicatethe status of operation of the air supply fan unit 20 includingsignaling error conditions and servicing conditions.

FIG. 3B is a block diagram illustrating inputs to a control system 400of the supply fan unit 20. The control system 400 may include thecontroller 120 and one or more programs, processes, and/or algorithmsexecuted by the controller 120 and stored in memory 146 (see FIG. 5),which operate to provide operating state instructions the supply fanunit 20 and/or other components. Inputs to the controller 120 includeAHU inputs 402 that supply AHU status information to the control system400. The AHU inputs 402 may include an operational status (e.g. on/offof the AHU), heating requests (W), cooling requests (Y), thermostatinformation, and/or user inputs provided through the AHU 160 and/orthermostat. The AHU inputs 402 may correspond to the control interface70 shown in FIG. 3A.

Sensor inputs 404 include information about the condition of the outsideair quality and/or environmental conditions. Specifically, sensor inputs404 may input readings acquired from the temperature and humiditysensors 34, 36, and/or from other suitable sensors such as arecontemplated hereinabove. The control system 400 further receives as aninput prediction table data 130 (see FIG. 3C). Still further, thecontrol system 400 may receive a standby mode instruction 406 initiatedby a user, the AHU 160, and/or in response to error detection.

Referring now to FIG. 3C, a prediction table 408 is graphicallyrepresented and is populated by the prediction table data 130. Theprediction table data 130 includes information derived from sensors(e.g. dew point (DP) and temperature (T)) and information regarding theduration and timing of the heating requests (W) and the cooling requests(Y) received by the control system 400 during the previous 48 hours.This information is added to the table according to a timestamp. Theprediction table 408 illustrates storage of sensor readings andheating/cooling requests for two days. Accordingly, the prediction tabledata 130 is stored each hour over the course of a previous time period,such as the past forty-eight hours. Alternatively, the prediction tabledata 130 may be stored more or less frequently than every hour (e.g.every 15 minutes, every 30 minutes, or every 6 hours), or may be storedaccording to a different timing pattern that is not uniform (e.g.humidity information may be stored more often during the day). Further,the prediction table data 130 may store more or less than 2 day/48 hoursof collected data (e.g. the predication table data may continuehistorical information for the previous week only the past few hours).Dew point information may be calculated according to known equationsand/or retrieved, based on humidity and temperature sensor readings,from prepared dew point tables.

The prediction table data 130 is comprised of one or more historicalinputs 410 received by the control system 400. These historical inputs410 are utilized by the control system 400 to predict the mostadvantageous time to perform required ventilation (i.e., ventilationnecessary to meet with air quality code requirements) for a nextoperational cycle. Referring once again to FIG. 4A, the control system400 operates to meet a requested level of ventilation measured in cubicfeet per minute (CFM) so as to comply with ventilation codes/industrystandards, minimize added humidity, and increase the satisfaction of ahomeowner or occupant of the serviced structure.

Taken alone or in any combination, the inputs (e.g. the AHU inputs 402,sensor inputs 404, one or more historical inputs 410) to the controlsystem 400 comprise operational data 401. This disclosure contemplatesadditional or alternative inputs to the control system 400, oroperational data, from one or more remote sources 403 (see FIG. 3B).Remote operational data 405 may include information received from theone or more remote data source 403 including, for example, cloud-storeddata, data provided from a weather service or near-real time weatherservice, and/or data received from networked supply fan units, AHUs,and/or other ventilation systems. Weather forecast information,historical temperature and dew point information collected from localweather stations, and/or air quality index data may supplement orsupplant the prediction table data 130. Further, all such information,both gathered from local sources such as the AHU 160 and the sensors 34,36, may be included with information from remote sources to comprise theoperational data 401 and develop the historical data 410 used by thecontrol system 400 to generate the prediction table data 130. Inresponse to the operational data 401, the control system 400 furthergenerates operating state instructions for the supply fan unit 20 and/orother ventilation system components. The controller 120 of the supplyfan unit 20 may communicate with the above-noted remote informationsources with a communications module 148 (see FIG. 5) integrated withinor operably coupled to the controller 120.

The control system 400 is described hereinthroughout as applied to thesupply fan unit 20. However, the control system 400 may instead beapplied to an air exchanger, air cycler, AHU, CFIS, and/or anothersuitable ventilation system in order to minimize humidity and/orheat/coolness transferred within a structure.

Still further, the control system 400 contemplated hereby may residewithin a controller in a thermostat, other wall control, and/or smarthome application. In such case, the control system 400 may makeventilation decisions, and generate operating state instructions for thesupply fan unit 20, based on at least a portion of the external inputsand/or historical data 410 (i.e. the operational data 401) discussedhereinabove. Additionally, the control system 400 may generate and/orsend operating state instructions to another ventilation system and/orsupply fan unit associated with the control system 400 and/or remotetherefrom.

FIGS. 4A and 4B illustrate available operating configurations andassociated operating conditions of an exemplary embodiment. FIG. 4Apresents a configuration table 100 a eight (8) available configurations(i.e., settings 1-3 and settings A-E) for control of fresh air inflowoperations. Each setting represents operating state conditionsassociated therewith, and on which the control system 400 executesoperational decisions and, in response to which, the controller 400generates operating state instructions. Configurations 1-3 (102) arebuilding code compliant configurations that determine a fresh air inflowrate parameter (see FIG. 4B). Configurations A-E (104) are customconfigurations that determine the fresh air inflow rate based onadditional factors. Example additional factors used for customconfigurations A-E (104) are outdoor low temperature limit and dewpoint, outdoor high temperature limit and dew point, and/or otheroperating condition limits of the AHU 160, such as a request for heatingor cooling. Section L (106) of the table shows operation conditionscontrolling operation independent from a trigger by the thermostatconnected to the AHU 160. Section R (108) of the table shows operationconditions controlling operation in the presence of triggers from thethermostat connected to the AHU 160. As depicted, example triggers fromthe thermostat may include a heating request or a cooling request. FIG.4B presents another configuration table 100 b including thereinavailable setting speeds for the fan 42 in order to set the desiredfresh air inflow rate parameter (measured in CFM) for two differentexample airflow capacities. This air inflow rate of ventilationparameter may be important for determining the duration of a ventilationoperating instruction. As a result, the rate of ventilation parametermay be determine in view of the ventilation timing parameter, or viceversa.

Referring now to FIG. 4C, another example of a configuration table 100 cis shown alongside a graphical representation of limit ranges 412 listedon the configuration table 100 c. The limit ranges 412 illustrate aventilation range 414 between upper and lower temperature/dew pointlimits or thresholds 416, 418. Within the ventilation range 414, thecontrol system 400 may generate an operating state instruction for thesupply fan 20 that conducts ventilation whereby fresh air is drawn inthrough the supply fan 20. Outside the ventilation range 414 and beyondthe upper and lower limits or thresholds 416, 418, the supply fan unit20 is prevented from conducting ventilation (e.g. entering a ventilationoperating state) so as not to draw in fresh air that is undesirably hot,cold, and/or humid. FIG. 4D illustrates still another exampleconfiguration table 100 d. In FIG. 4D the configuration table 100 d,includes ventilation cycle time periods 420 and decision triggers 422.The ventilation cycle time periods 420 and the decision triggers 422correspond to particular settings of the control interface 70 shown inFIG. 3A. The decision trigger 422 may be temperature or humidity (e.g.dew point) such that when the decision trigger 422 is humidity, theventilation timing parameter, which determines the timing and durationof ventilation, within the ventilation cycle time period 420 or (OC)(see FIG. 8), is optimized based on historical dew point data.Alternatively, when the decision trigger 422 is temperature, theventilation timing parameter is optimized based on historicaltemperature data. In yet another example, a combination of thehistorical dew point data and historical temperature data may be used tooptimize the ventilation timing parameter and/or the ventilation rateparameter, which determines the air inflow rate (see FIG. 4B). Theoptimization and/or prioritization (during which control of humidity ortemperature is optimized) may be executed based on the historical data410 or the prediction table data 130 generated therefrom. Additionally,within the ventilation cycle time period 420 or operation cycle.Optimization may correspond to limiting, ending, and/or preventingventilation when a temperature or dew point limit shown in theconfiguration table 100 d is exceeded or not reached. Further, the limitlisted for either temperature or humidity in each of the selectablemodes defines the ventilation range 414 (see FIG. 4C). Also, the upperand lower limits or thresholds 416, 418, may be modified in response toa heating and/or cooling request received from a thermostat orthermostat control 168 (see FIG. 6).

FIG. 4E is a map graphically illustrating, by region in association witha legend, preferred modes of the configuration tables of FIGS. 4A-4D.Different modes may be more or less suitable for particular climates. Itmay be desirable to use only certain modes depending on the geographiclocation of the supply fan unit 20.

Referring now to FIG. 5, a schematic diagram illustrates the structureof components participating in the operation of the supply fan unit 20of the present disclosure. The diagram presents the controller 120, 62receiving a number of input signals. The input signals include initialsettings 110, sensor signals 112, first control signals 114, and secondcontrol signals 116. The initial settings 110 control operation in apost-installation mode before collection of data, such as signal inputs,for entry in a normal mode. The sensor signals 112 are received from thetemperature sensor 34 and the humidity sensor 36. The control signals114 are received/input from the control interface 70, and the controlsignals 116 are collected from the control responsible for triggeringoperations of the AHU 160 (see wiring schematics of FIG. 7). Thecontroller 120 further operates based on the prediction table data 130.The controller 120 controls two processes: a sampling process 142 (seeFIG. 9) and a fresh air supply process 144. The controller 120 isfurther adapted to feed the prediction table data 130 with new dataaccording to the processes of FIGS. 8 and 9. Programs and algorithmsused by the controller 120 are stored in an internal memory/memorymodule 146 of the controller 120. According to an embodiment, coderelative to the programs and algorithms may be stored on a sharednon-volatile memory also storing the prediction table data 130. Data andsignals illustrated on FIG. 5 are time-varying data and signals. Thediscussed programs and algorithms may be stored in the memory module 146within the controller 120 during manufacture and may be updated duringmaintenance of the supply fan unit 20 performed by a maintenancetechnician. Additionally, a communications module 148 may be integratedwithin and/or operably coupled with the controller 120. Thecommunications module 148 may facilitate wired and/or wirelesscommunications with the AHU 160, external sources of data and/orcontrol, and/or with the sensors 34, 36. The communications module 148operate according to any suitable protocol such as Bluetooth, Wi-Fi,ZigBee, near field communication (NFC), and/or radio-frequencyidentification (RFID).

FIG. 6 depicts a high-level flow chart of control processes for the airsupply fan unit 20. More detailed processes of the controller 120 areshown and described with respect to FIGS. 10-15; however, FIG. 6represents more general relationships between the control processes forthe air supply fan unit 20 and the AHU 160. A starting/initializationprocess 210 operates the air supply fan unit 20 based on initialsettings. A managing and/or waiting events process 212 waits for sensorinput and control information. A first data exchange process 214receives and updates prediction table data based on a currentoperational state. A second data exchange process 216 receives and/ortransmits control signals according to condition changes in the buildingdetected by the wall control. Change of state process 218 is performedby the AHU 160 and provides updates concerning state changes of the AHU160, which may trigger a determination of a ventilation decision process222 performed by the supply fan unit 20. If no determination of theventilation decision process 222 is triggered by an AHU operation, thena time-out algorithm 220 (target timer reached) triggers determinationof the ventilation decision process 222 of the supply fan unit 20. Eachdetermination performed by the ventilation decision process 222 isregistered by the managing and/or waiting events process 212. In view ofthe registered determinations of the ventilation decision process 222,the managing/waiting events process 212 manages the operational periodsof the supply fan unit 20 to determine a next period of operation.Referring now to FIG. 7, a wiring schematic diagram showsinterconnection between the supply fan unit 20, the AHU 160, and the AHUcontrol 166 and/or thermostat control 168. In accordance with thisschematic, the signals transmitted by the AHU control 166 to the AHU 160may trigger heating and/or cooling. These signals may also be registeredby the supply fan unit 20, which may tap communications between thethermostat and AHU controls 168, 166 and the AHU 160 to eavesdropcontrol signals passed therebetween. The control signals tapped by thesupply fan unit 20 may be used as inputs to the controller 120.

FIG. 8 illustrates an example operation cycle of the supply fan unit 20.The supply fan unit 20 may operate according to a cycle (nD) with “D”referring to a day-long period and “n” the number of day-long periodssampled to develop the prediction table data 130 (FIG. 5). The day-longcycle (D) is further divided in collection period(s) (CP), eachcollection period typically being one (1) hour in duration. Thecollection period defines a period during which data collection isperformed on fresh air and registered in the prediction table. Dataconcerning fresh air is collected through a sampling process and/or afresh air supply process. During each collection period, a sample offresh air is evaluated to monitor the characteristics of the fresh airover time. Finally, the day-long period is separated into operationcycles (OC) with parameters used in each operation cycle based on theconfigured settings of the air supply unit 20. The parameters may definelimit conditions and fresh air quality/characteristic requirements. Thecontroller 120, based on the algorithm stored in the non-volatile memory146 readable by the controller 120, determines when to perform a freshair inflow operation to meet operating and/or limit conditions. Further,for each collection period, a number of sample(s) “n” are collected foreach of the temperature sensor 34 (indicated by Tij in FIG. 8) and thehumidity sensor 36 (indicated by Hij in FIG. 8). When new data iscollected, older data may be pushed from the collection of informationfor the prediction table 130. For example, data points may bereplacement one-for-one in the prediction table 130 with each new datapoint replacing the oldest present sensor readings. Other exampleembodiments/algorithms may replace data according to another desiredmethodology, as applicable. For example, calculations may be performedto identify trends within the data of the prediction table 130 and/or toidentify outlier data points. Accordingly, data points discarded as newdata points are collected may be adapted according to different goals,as applicable. In exemplary embodiments, the number of data pointscollected for use in establishing the prediction table 130 may be heldconstant.

Again referring to FIG. 8, management of the prediction table data isillustrated. In FIG. 8, a collection period identifier (i) ranges fromzero (0) to 23, and a sample day identifier (j) ranges from zero (0) ton−1. When new data is collected the sample day identifier (j) of alldata of the same temperature (T), humidity (H), and collection periodidentifier (i). This results in a previously collected sample datapoint, wherein the sample day identifier (j) is equal to “n”, beingdropped from the prediction table data 130. This chart corresponds to,but differently represents, the historical temperature and humidity data410 of the prediction table 408 shown in FIG. 3C. Based on the Tij andHij present in the prediction table data 130 at any time, first andsecond prediction curves 152 and 154 are defined for predicting thecharacteristics of the fresh air. These first and second predictioncurves 152, 154 represent temperature prediction and humidity predictionfor a normal day cycle (D). Further, this example data set may bemanaged with relative ease in the non-volatile memory module 146 as aknown-size array. A number of algorithms are suitable for obtaining thedesired prediction curves based on the value of “n” and the selectedlength of the collection period. The number (n) and the length of thecollection period represent relative values of samples based on an ageof the sample or a gap between a sample and another day-long periodsample and/or neighboring day-long period samples. Selection of analgorithm may be customizable based on available hardware, samplingconditions, data sensibility, application goals, and/or other suitable.Dependent on application, cost and precision may be appropriatelybalanced. FIG. 8 shows operation cycles representing a heating mode andcooling mode of the AHU 160. The data collected for heating and coolingmodes are continuous data since the supply fan unit 20 taps on theconnection between the AHU 160 and the wall control unit therefor. Thisconfiguration provides for signal reading/registering at any time.

Referring now to FIG. 9, when no sampling has been performed during thecollection period and/or when likelihood of sampling being triggeredduring the remaining portion of the collection period is below a certainthreshold, the controller 120 triggers a sampling mode. Triggeredsampling may refer to sampling performed during normal operation whenfresh air is being drawn into the supply fan unit 20. Sampling comprisesmoving the damper 52 to an open position and powering up the fan 42during a regulated period (e.g., 5 minutes) so that the air in thesupply fan unit 20 is fresh air that relatively un-influenced by airconditions within the building interior. Further, sampling includescollecting signals from the temperature sensor 34 and the humiditysensor 36 and transmitting the signals to the prediction table 130 forregistry and storage therein. Triggered sampling follows the sameoperation as autonomous sampling other than that the sampling operationis triggered by AHU operation instead of autonomously during normaloperation.

The steps of the flow chart include determining if a sampling has beenperformed (S12) during a current collection period (CP), establishing asampling time (S14), receiving an AHU operation signal (S22), performingthe sampling (S32), and transmitting signals to the prediction table130. The transmitting step involves communicating AHU operation data tothe prediction table (S24) and transmitting signals of fresh aircharacteristics to the prediction table (S34). After these steps, a nextstep includes waiting for a next collection period (CP) to be initiated(S42). The flow chart further comprises establishing whether thesampling time as been reached without any sampling being performed (S16)and autonomously triggering a sampling process (S18), as applicable. Theautonomously triggering a sampling process step (S18) is followed bysteps (S34) and (S42).

Further, based on the present use of the prediction table(s) and inresponse to the AHU control signals, the present supply fan unit 20 iscapable of improving the time and condition of use to prevent, forexample, i) drawing high-humidity fresh air into building without thehigh-humidity fresh air being process by the AHU 160 operating in acooling mode, and ii) optimizing concurrent operation of the AHU 160 andthe supply fan unit 20. Accordingly, better control of operationalconditions may be attained, as the characteristics of the fresh airinflow supplied into the building are monitored and/or controlled.

Referring now to FIG. 10, a main operating process 300 is illustrated bya flowchart beginning with a main routine step 302. At step 304, anoperating system and control variables are initialized. This includes adamper motor initialization step 306, a humidity sensor initializationstep 308, and a wireless communication module (e.g. Wi-Fi)initialization step 310. In a next step 312 a speed setting for the fan42 (see FIG. 4B) is determined and set according to the configurationtable 100 b. Settings are read from the potentiometers 74 (see FIG. 3A)at step 314. Next, a self-check may be performed and the predictiontable data 130 is cleared, if same is currently stored within the memorymodule 146.

At step 318, AHU control signals are accepted as inputs (see FIG. 7).Following receipt of the AHU control signals, the damper 52 is checkedfor an error state at step 320 while a ventilation decision process 322is performed to determine the current ventilation schedule based on theearlier initialized variables and the prediction table data 130. Insteps 324, 326 status LEDs in a user display are updated and the mainoperation process 300 is tracked by a main loop timer 328. While themain loop timer 328 is unexpired, the main operating process 300continues to poll for AHU control signals at step 318. Once the mainloop timer 328 expires, the main operating process 300 updates theprediction table data 130 and other variables through a variable/counterdata update process 330.

The ventilation decision process 322 is illustrated by a flowchart inFIG. 11. At step 332, the controller 120 checks whether values from thesensors 34, 36 have been acquired and whether ventilation is completefor a current ventilation cycle time 420 (see FIG. 4D) or operationcycle in FIG. 8. If sensor values have not yet been acquired, then dewpoint and temperature values are read from the humidity and temperaturesensors 34, 36 and compared against the dew point and temperature limitsof the configuration table(s) 100 (see FIGS. 4A, 4C, and 4D) at step334. The control system 400 monitors ventilation timing and may performsensor readings only after five minutes of continuous ventilation hasbeen completed. This may provide more consistently accurate and reliablesensor readings because it ensures that the sensors 34, 36 measure thequalities of incoming air. In example embodiments where the sensor aredisposed remote from the supply fan unit 20, such as exterior theserviced building or structure, a different protocol for reading thesensors may be implemented. For example, sensor readings may be takenover a period of time (e.g. five minutes) and averaged to reach valuefor use by the control system 400. If the temperature and humidityvalues acquired from the sensors 34, 36 are within the limits defined bythe configuration table 100, then ventilation is conducted at step 336.However, if the ventilation cycle is complete or the sensor readings arenot within the limits defined by the configuration table 100, thenventilation is stopped at step 338.

The variable/counter data update process 330 is illustrated by theflowchart of FIG. 12. According to this flowchart, values of thecounters and other variables that track operation of the supply fan unit20 are updated. The variable/counter data update process 330 takes placeupon expiration of the main loop timer 328, as shown in FIG. 10. Atintermediate step 340 of the variable/counter data update process 330,the prediction table data 130 is updated near the end of each hour thatthe supply fan unit 20 is operated. At ventilation target predictionprocess 342, ventilation targets are updated according to the predictiontable data 130, if a new ventilation cycle has been initiated.

FIGS. 13 and 14, respectively, depict with flowcharts a startventilation process 344 and a stop ventilation process 346. During thestart ventilation process 344 of FIG. 13, at step 348 the controller 120checks an operational state of the fan 42. If the fan 42 is alreadyoperating then ventilation is in progress and the process ends. However,if the fan 42 is off, then the damper 52 is opened at step 350 beforethe fan 42 is activated.

The stop ventilation process 346, at step 352, checks whether the damper52 is closed. If the damper is currently closed, then ventilation is notoccurring and the stop ventilation process 346 ends. However, if thedamper 52 is open, then the fan 42 is turned off at step 354 and thedamper is closed at step 356.

Steps of the ventilation target prediction process 342 are shown in FIG.15. At steps 358 and 360, control signals from the potentiometers 74(see FIG. 3A) are polled. In response to these control signals, at step362, the prediction table data 130 is checked. If all prediction tabledata 130 is valid, then ventilation targets for time and duration ofventilation are set in accordance with the prediction table data 130 atstep 364. However, if the prediction table data 130 is not valid, suchas when less than forty-eight hours of prediction table data 130 hasbeen collected, then the amount of ventilation required to comply withair quality codes is scheduled equally across the length of theoperation cycle time 420 (e.g., in equal time windows during each hourof the operation cycle).

INDUSTRIAL APPLICABILITY

The present supply fan unit has potentially the following advantagesover current existing solutions. The supply fan unit 20 has anadjustable fan speed providing for adjustment of the ventilation ratedepending on evaluation of how favorable a condition is for fresh airinflow. The supply fan unit 20 has a built-in algorithm, stored in anon-volatile memory readable by the controller 120, to optimizeventilation rate(s) when outside conditions are favorable. The supplyfan unit 20 has a built-in algorithm, stored in a non-volatile memoryreadable by the controller 120, to potentially optimize ventilationrate(s) when inside conditions increase requirements. According to anembodiment, a pressure sensor, disposed on the outflow side of thedamper 52, detects AHU operation without requiring an electricalconnection to the AHU 160. The supply fan unit 20 may increase comfortby managing ventilation rate(s) according to AHU running time. Thesupply fan unit 20 may be interlocked with one or more exhaust fans toproduce a balanced ventilation airflow.

According to an exemplary embodiment, a method controls inflow of freshair in a home comprising an AHU performing at least one of heating,ventilating, and air conditioning of the home. The method comprises thesteps of: collecting sensor signals indicative of fresh aircharacteristics over a sampling period, wherein the sensors are at leastone of a humidity sensor and a temperature sensor, and registering thesensor signals over a cycle. The method further comprises establishingan operation profile indicative of at least one operation ofinflow/intake of fresh air during an operation period, monitoringoperation states of the AHU during the operation period, and performingthe at least one operation(s) of inflow of fresh air based on theestablished operation profile as well as on the monitored operationstates of the AHU. Further, according to this method, the samplingperiod is smaller than the operation period, and the operation period issmaller than the cycle.

According to embodiments, as discussed hereinthroughout, the length ofthe sampling period, i.e., collection period (CP), the length of theoperation period (OP), and the length of a cycle (nD) may vary. Further,the length of the collection period (CP) may be about one hour, leavingtime for readings of the integrated sensors to reach a stabilizedcondition before registering/storing the respective readings. Stillfurther, the length of the collection period (CP) may be smaller.Additionally, in exemplary embodiments, the length of the collectionperiod (CP) may be in real time or near-real time, based on the natureand location of the sensors. According to an example embodiment, thelength of the operation period (OP) may be about 3 or 4 hours so as tocomply with existing building regulations. Further, the length of theoperation period (OP) may be an integer multiple of the length of thecollection period (CP).

According to an exemplary embodiment, monitoring operation states of theAHU during the operation period is performed in real time or near-realtime. The real time and/or near-real time monitoring may furthercomprise registering/storage of the operation states. Further, thelength of the cycle (nD) may be an integer multiple of the length of aday. According to exemplary embodiments, the length of a cycle is 2 or 3days. According to an embodiment, the method further comprisescontrolling a controllable inflow means operable to provide an inflow offresh air. Also according to embodiments, the controllable inflow meansis controllable by at least one of inflow operation duration and inflowrate of fresh air during inflow operation. The method mayalso/alternatively estimate and store data regarding the environmentincluding, but not limited to, the current hour, the current season,etc., which may be used by the algorithm to optimize the decision-makingprocess.

While preferred embodiments have been described above and illustrated inthe accompanying drawings, it will be evident to those skilled in theart that modifications may be made without departing from thisdisclosure. Such modifications are considered as possible variantscomprised in the scope of the disclosure.

Headings and subheadings, if any, are used for convenience only and donot limit the invention. The word exemplary is used to mean serving asan example or illustration. To the extent that the term include, have,or the like is used, such term is intended to be inclusive in a mannersimilar to the term comprise as comprise is interpreted when employed asa transitional word in a claim. Relational terms such as first andsecond and the like may be used to distinguish one entity or action fromanother without necessarily requiring or implying any actual suchrelationship or order between such entities or actions.

Phrases such as an aspect, the aspect, another aspect, some aspects, oneor more aspects, an implementation, the implementation, anotherimplementation, some implementations, one or more implementations, anembodiment, the embodiment, another embodiment, some embodiments, one ormore embodiments, a configuration, the configuration, anotherconfiguration, some configurations, one or more configurations, thesubject technology, the disclosure, the present disclosure, othervariations thereof and alike are for convenience and do not imply that adisclosure relating to such phrase(s) is essential to the subjecttechnology or that such disclosure applies to all configurations of thesubject technology. A disclosure relating to such phrase(s) may apply toall configurations, or one or more configurations. A disclosure relatingto such phrase(s) may provide one or more examples. A phrase such as anaspect or some aspects may refer to one or more aspects and vice versa,and this applies similarly to other foregoing phrases.

All numbers and ranges disclosed above may vary by some amount. Whenevera numerical range with a lower limit and an upper limit is disclosed,any number and any included range falling within the range arespecifically disclosed. In particular, every range of values (of theform, “from about a to about b,” or, equivalently, “from approximately ato b,” or, equivalently, “from approximately a-b”) disclosed herein isto be understood to set forth every number and range encompassed withinthe broader range of values. Also, the terms in the claims have theirplain, ordinary meaning unless otherwise explicitly and clearly definedby the patentee. Moreover, the indefinite articles “a” or “an,” as usedin the claims, are defined herein to mean one or more than one of theelement that it introduces. If there is any conflict in the usages of aword or term in this specification and one or more patent or otherdocuments that may be incorporated herein by reference, the definitionsthat are consistent with this specification should be adopted.

A phrase “at least one of” preceding a series of items, with the terms“and” or “or” to separate any of the items, modifies the list as awhole, rather than each member of the list. The phrase “at least one of”does not require selection of at least one item; rather, the phraseallows a meaning that includes at least one of any one of the items,and/or at least one of any combination of the items, and/or at least oneof each of the items. By way of example, each of the phrases “at leastone of A, B, and C” or “at least one of A, B, or C” refers to only A,only B, or only C; any combination of A, B, and C; and/or at least oneof each of A, B, and C.

In one aspect, a term coupled or the like may refer to being directlycoupled. In another aspect, a term coupled or the like may refer tobeing indirectly coupled. Terms such as top, bottom, front, rear, side,horizontal, vertical, and the like refer to an arbitrary frame ofreference, rather than to the ordinary gravitational frame of reference.Thus, such a term may extend upwardly, downwardly, diagonally, orhorizontally in a gravitational frame of reference.

The title, background, brief description of the drawings, abstract, anddrawings are hereby incorporated into the disclosure and are provided asillustrative examples of the disclosure, not as restrictivedescriptions. It is submitted with the understanding that they will notbe used to limit the scope or meaning of the claims. In addition, in thedetailed description, it can be seen that the description providesillustrative examples and the various features are grouped together invarious implementations for the purpose of streamlining the disclosure.The method of disclosure is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, as the claims reflect,inventive subject matter lies in less than all features of a singledisclosed configuration or operation. The claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparately claimed subject matter.

The use of the terms “a” and “an” and “the” and “said” and similarreferences in the context of describing the invention (especially in thecontext of the following claims) are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. An element proceeded by “a,” “an,” “the,” or“said” does not, without further constraints, preclude the existence ofadditional same elements. Recitation of ranges of values herein aremerely intended to serve as a shorthand method of referring individuallyto each separate value falling within the range, unless otherwiseindicated herein, and each separate value is incorporated into thespecification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the disclosureand does not pose a limitation on the scope of the disclosure unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe disclosure.

Numerous modifications to the present disclosure will be apparent tothose skilled in the art in view of the foregoing description. Preferredembodiments of this disclosure are described herein, including the bestmode known to the inventors for carrying out the disclosure. It shouldbe understood that the illustrated embodiments are exemplary only, andshould not be taken as limiting the scope of the disclosure.

What is claimed is:
 1. A ventilation system for supplying a user controlled quantity of outside air into a building structure during a predetermined period of time, comprising: a controller configured to be operably coupled to a memory configured to store environmental data collected from at least one environmental sensor about outside air; wherein the controller is configured to generate a prediction table based on the environmental data; wherein the controller is configured to predict when during the predetermined period of time to supply the user controlled quantity of outside air into the building structure, and the controller is further configured to provide instructions to supply the user controlled quantity of outside air to the building.
 2. The ventilation system of claim 1, further comprising at least one environment sensor.
 3. The ventilation system of claim 2, further comprising a fan and the controller instructs the fan to move fresh air into the building.
 4. The ventilation system of claim 3, wherein the controller further instructs the fan in response to a thermostat instruction and the thermostat instruction comprises at least one of a heating call, a cooling call, and a standby call.
 5. The ventilation system of claim 1, wherein the pre-defined time period is two previous days.
 6. The ventilation system of claim 3, wherein the fan is a supply fan that provides fresh air from an exterior environment to the ventilation system.
 7. The ventilation system of claim 1, wherein the controller further operates a damper to control provision of the user controlled quantity of outside air.
 8. A ventilation system for supplying a user controlled quantity of outside air into a building structure during a predetermined period of time, comprising: a controller operable coupled to a memory configured to store a prediction table of temperatures and dew points, wherein the prediction table is generated based on environmental data collected from at least one sensor; wherein the controller is configured to predict, based on predicted temperatures or dew points in the prediction table, when during the predetermined period of time to supply the user controlled quantity of outside air into the building structure; wherein the prediction table indicates a range of temperatures and dew points during at least one mode and each of the modes corresponds to one or more threshold defined by the prediction table.
 9. The ventilation system of claim 8, wherein the controller determines operating state instructions of the system according to the mode defined by the prediction table.
 10. The ventilation system of claim 9, wherein the controller determines the operating state instructions of the ventilation fan according to a temperature and humidity observed by the at least one sensor.
 11. The ventilation system of claim 8, wherein the one or more threshold defined by the prediction table is modified in response to a thermostat instruction received by the controller.
 12. The ventilation system of claim 8, wherein the prediction table includes data from a remote source.
 13. The ventilation system of claim 12, wherein the remote data source includes one of historical weather data, one or more near real-time weather service, and data gathered by other ventilation systems.
 14. The ventilation system of claim 13, wherein a communications module networks the controller with one or more other ventilation systems.
 15. A method of controlling inflow of a user controlled quantity of outside air, the method comprising: storing air values indicative of outside air characteristics over a historical time period; generating a prediction table of predicted temperatures or dew points based on the stored air values; predicting, based on predicted temperatures or dew points in the prediction table, when during a predetermined period of time to allow inflow of the user controlled quantity of outside air; generating instructions to allow the inflow of the user controlled quantity of outside air.
 16. The method of claim 15, collecting of the air values from one or more sensors.
 17. The method of claim 15, wherein the historical time period is two days.
 18. The method of claim 16, wherein the one or more sensors comprise a humidity sensor, a temperature sensor, a pressure sensor, and a flow rate sensor.
 19. The method of claim 15, wherein the predicted temperatures or dew points are stored as a prediction table. 